This invention relates to a novel polyphenylene ether resin composition which is excellent in extruding and blow molding properties, and relates to molded products manufactured therefrom.
Polyphenylene ether has a high glass transition temperature of 210.degree.-220.degree. C. along with high heat resistance, and when molten, it becomes amorphous. It is therefore characterized by its high dimensional accuracy. However, the resin is poor in molding properties and chemical resistance, so it is not appropriate for the resin to be used by itself for manufacturing injection molded or extrusion blown products.
On the other hand, not only does polyamide have a high melting temperature or high glass transition temperature, but it also has low melt viscosity as well as high chemical resistance, so it is used for injection molding. However, polyamide has low melt-tension, therefore it causes high parison sag during blow molding which leads to difficulty in obtaining large size blow molding product by the single use of polyamide. In present blow molding, it is the condition that only a small amount of polyamide is used as gas barrier layer for extruding multi-layer bottle or tank together with polyolefine of high melt-tension.
In recent years, many attempts have been made to obtain polymer alloys which simultaneously have both polyphenylene ether and polyamide features. As disclosed in Japanese Patent Laid-open Nos. 47432/1981, 49753/1981, 36150/1982, etc., polymer alloys for injection molding are provided which have improved mechanical properties, heat resistance and chemical resistanse of both resins. However, when used for blow molding use, the alloys have turned out to be unpractical because they produced a great degree of ununiform section of products due to the great parison sag thereof.
An object of this invention is to substantially improve the parison sag properties of resin composition mentioned above in blow molding while allowing the composition to have high quality in the mechanical properties, heat resistance and chemical resistance just as in those of said polymer alloys. The compositions are, further expected to be used for automotive parts such as a portion of automotive exrerior panels, fuel tanks, oil tanks, radiators, duct hosepipes, harness tubes, air spoilers, bumpers, side protectors, seats, rear shelfs etc. and housings for OA machines, case for musical instruments, etc., or medicine bottles etc.